My point was about that each of the BSD's use pkgsrc in a different way and
the releases from FreeBSD, NetBSD, OpenBSD or DflyBSD don't all rely on the
exact same packages for every release (i.e. NetBSD 6 and FreeBSD 9 do not
use the same version of GNOME-2 desktop; poor example), and that generally
per BSD release they generally blob the binaries that are compatible for
that release together.

No, pkgsrc is one for everyone, unless someone maintains his own branch.
As far as I know, only DragonFly and SmartOS do, though nothing serious
stops them from using original distribution. Thus NetBSD 6 and FreeBSD 9 use
the same version of GNOME, provided that they use supported pkgsrc branch.

DragonFly has a git mirror mirror of the pkgsrc cvs repository, but its contents are identical to what is in cvs. I would not classify this as "maintaining its own branch". We use the same distribution as NetBSD.